1: On plate inside engine bay.
2: On plate riveted to dash (passenger side - visible through windscreen).
3: On chassis around the driver's seat area.

1 and 2 are there on my truck. I took a torch outside and grovelled around under the truck looking for 3. But could not seem to find it. I guess it may be behind one of my rock slider mounting points. However, there is no chance I am going to be removing sliders today to find it. That is an 8 hours job on its own...